Most power supply devices provide one or more output power to meet a load requirement or generate two output power for a backup or compensation of power. However, a majority of the traditional power supply devices use a tap winding of a transformer or a plurality of winding couplings to achieve the function of providing a plurality of output power to drive different loads. An “Alternate-current distributed power supply device” is disclosed in R.O.C. Pat. No. M244645, FIG. 2 of the patent specification shows the structure of the aforementioned traditional power supply device, and FIG. 5 further discloses a transformer that uses a circuit structure having a plurality of windings to provide different voltages through a multiple of output paths, but the tap winding of the transformer or the structure of a plurality of windings actually involves a complicated manufacturing procedure, slows down the production rate, and increases the cost. To avoid using components of a higher cost, manufacturers provide another multi-output power circuit structure that uses two converters for generating two output power as shown in FIG. 1. FIG. 1 shows a circuit block diagram of a traditional power supply device, wherein the power supply device is connected to an electric power source 1 for obtaining input power. After going through a rectifier unit 2 and a power correction unit 3, the power correction unit 3 obtains the input power and modulates its voltage or power factor. The power correction unit 3 is connected to a first converter 4 and a second converter 5, and the first and second converters 4, 5 obtain the input power from the power correction unit 3 to generate a first output power and a second output power and output the first and second power from a first output terminal 41 and a second output terminal 51 respectively. The first and second converters 4, 5 obtain a feedback signal from the first output power or the second output power to control the output timing and power independently. Although the power supply devices can back up each other independently to avoid the use of components of a higher cost, theoretically the output timing of the two converters should be synchronous, and the boost time and step-down time of the voltage of the first output power and the second output power should be equal, yet there is a time difference between the timings of the voltages of the two converters from the startup to the final stage, so that the boost time and the step-down time cannot be synchronized. Obviously, the prior art requires improvements.